Epidemiological studies have suggested that exposure to 60-Hz electromagnetic fields (EMFs) may have adverse effects on the nervous system. However, there is currently little information regarding how EMFs and neural cells may interact. The goal of our research is to provide data that will begin to bridge this gap. Results of preliminary studies show tha isolated adrenal medullary chromaffin cells, a well-characterized cell culture model of neural-type cells, undergo an increase in intracellular calcium in response to a magnetic flux density of around 1 mT. In these studies, intracellular calcium level was monitored by fluorescence video imaging of the cells during EMF exposure. The overall alm of the proposed research is to continue to use fluorescence imaging of intracellular calcium in chromaffin cells to define the EMF-induced calcium response as a function of several EMF parameters. The specific field exposure parameters to be studied are: 1) the range of magnetic flux densities that elicit responses; 2) the frequencies of EMF that cause changes in calcium;: 3) the relationship between the duration of the EMF exposure and calcium responses; 4) the effect of single versus multiple EMF exposures on calcium responses; and, 5) the effect of transients on calcium responses. Data derived from these studies will be important for helping to evaluate more critically whether environmental EMFs present a human health risk since EMF exposures in school, residential, occupational and transportation environments represent a complex mixture of field intensities, exposure durations, frequencies and transients.